1. Field of the Invention
The present invention relates generally to an apparatus and method for the treatment of fractures of the proximal femur including the neck of the femur and the intertrochantric region.
2. Brief Description of the Prior Art
In treatment of the fracture of the femoral neck it is necessary to maintain angular stability of the head fragment to maintain an anatomical reduction postoperatively. It is also desirable to compress fracture site intra-operatively and then to stabilize the bone fragments by not allowing any further axial or angular movement. Since axial movement of the bone fragment resulting in shortening of the neck of the femur will result in reduced physical functioning, particularly in younger patients, it is desirable to stabilize the fracture postoperatively.
Many locking plates are available that allow stabilization of bone fragments. Conventional locking plates (also known as bone plates) have a plate that is attached to the fragments of the fractured bone via screws that are inserted in the bone through screw holes in the plate. The screws of the conventional locking plates have threads on the head portion in addition to the threads on the shaft. The threads on the head portion have a greater core diameter than the threads on the shaft but both threads have same pitch. When the screw is advanced in the bone and the head of the screw is in the screw hole of the bone plate, the threads on the screw head engage matching threads in the screw hole. This locks the screw in place and prevents it from moving in the axial direction post operatively. However, such bone plate system cannot be used to compress the fracture site. In another conventional bone plate system used for femoral neck fracture a compression screw is used. The compression screw head does not have the threads and therefore may be rotated further after its head has reached the final axial position thereby compressing the fracture site. A separate end cap is then screwed in the compression screw hole of the bone plate to prevent the screw from moving back in the axial direction.
These bone plate systems require a separate step of installing an end cap to prevent post operative axial movement of the screw. Therefore, there is a need for further improvement in bone plate systems to provide an easy to use plate system that facilitates intra-operative compression and at the same time provides angular and axial stability post operatively.
As used herein, when referring to bones or other parts of the body, the term “proximal” means closer to the heart and the term “distal” means more distant from the heart. The term “inferior” means toward the feet and the term “superior” means towards the head. The term “anterior” means towards the front part of the body or the face and the term “posterior” means towards the back of the body. The term “medial” means toward the midline of the body and the term “lateral” means away from the midline of the body.